Transmit power amplification control for wireless device

ABSTRACT

A system and method are disclosed for controlling transmit power amplification in a wireless transmitting device. A processor receives data to determine whether a communication channel from a transmitting device to a receiving device is strong enough to support a target data transmit rate of the devices with a power amplifier either on or off. The processor controls a switching device between a data transmitter circuit and the transmitter&#39;s antenna based on the quality of the communication channel. In a first state, the switching device connects the data transmitter circuit to the power amplifier to increase the strength of the signal communicated to the antenna. In a second state, the switching device bypasses the power amplifier. The power amplifier is turned off when the switch is in the second state, thereby decreasing the power consumed by the transmitting device as it transmits data at the target data transmit rate.

RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.12/123,281, filed May 19, 2008, which claims the benefit of U.S.Provisional Application No. 60/938,816, filed on May 18, 2007, both ofwhich are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to the field of wireless communication,and more particularly to selectively activating and deactivating a poweramplifier in a wireless device for controlling the power of a datatransmit signal.

2. Related Art

The maximum rate of data transfer (measured as megabits per second(Mbps), for example) from a wireless transmitting device to a receivingdevice may be dependent upon one or more of the following: thecommunication protocol, the antenna configurations of the devices, thequality of the communication channel, the power level of the transmittedsignal, whether the receiving device includes a power amplifier, thedistance between the devices, and other factors. Devices are configuredto transfer (transmit and receive) data up to a maximum data transferrate that is typically specified by the communication protocol used.Many transmitting devices include a power amplifier to increase thestrength of the data transmit signal. The increased strength of thetransmit signal helps increase the data transfer rate up to the maximum(i.e., rated) data transfer rate.

The power amplifier in a transmitting device continuously consumes asignificant amount of power. For example, a power amplifier in awireless local area network (WLAN) chip may consume more than fiftypercent of the total power supplied to the chip in transmit mode. As aresult, the continuous operation of the power amplifier significantlydecreases the battery life of the device. An improved approach isdesirable.

BRIEF SUMMARY

The following embodiments relate to systems and methods of activating ordeactivating a power amplifier in a wireless data transmitter based onthe quality of a communication channel and/or the distance between atransmitting device having the data transmitter and a receiving device.The quality of the communication channel may be based on data indicatingthe strength of the communication channel, as an example. If thestrength of the communication channel is great enough, and/or if thewireless data transmitter and the receiving device are within apredetermined distance, the power amplifier may be powered down topreserve the battery life of the transmitting device.

An apparatus comprises a transmitter to communicate a data transmitsignal to a switch and a processor to control the switch based on atleast one parameter of a wireless communication channel. The processorcontrols the switch to maintain a target data transfer rate and maydetermine a distance between a transmitting device and a receivingdevice. In a first state the switch communicates the data transmitsignal to bypass a power amplifier, and in a second state the switchcommunicates the data transmit signal to the power amplifier. The atleast one parameter may be selected from a group consisting of: asuccessful data transfer rate from the transmitter to a receivingdevice, a received signal strength indication, and a packet error ratio.The processor may be configured to activate the switch to the firststate if the at least one parameter is above a first threshold, andactivate the switch to a second state if the at least one parameter isbelow a second threshold. Also, the processor may switch the poweramplifier off if the at least one parameter is above the firstthreshold, and switch the power amplifier on if the at least oneparameter is below the second threshold. The first threshold may beequal to the second threshold. The transmitter and the processor maycomprise a wireless local area network chip.

A method comprises communicating a data transmit signal to a poweramplifier if at least one parameter of a wireless communication channelis below a first threshold. The data transmit signal bypasses the poweramplifier if the at least one parameter is above a second threshold. Atarget data transfer rate is maintained through the wirelesscommunication channel. The distance between a transmitting device and areceiving device is determined based on the at least one parameter.

An apparatus comprises means for communicating a data transmit signal toa power amplifier or to bypass the power amplifier based on at least onequality parameter of a wireless communication channel. The apparatus mayalso include one or more of means for activating a switch to a firststate if the at least one quality parameter is above a first threshold,and activating the switch to a second state if the at least one qualityparameter is below a second threshold; means for switching the poweramplifier on or off based on the at least one quality parameter; meansfor maintaining a target data transfer rate; and means for determining adistance between a transmitting device and a receiving device.

A computer readable storage medium has processor executable instructionsto communicate a data transmit signal to a power amplifier if at leastone parameter of a wireless communication channel is below a firstthreshold and communicate the data transmit signal to a signal path tobypass the power amplifier if the at least one parameter is above asecond threshold. The computer readable storage medium may also haveprocessor executable instructions to maintain a target data transferrate through the wireless communication channel and/or determine adistance between a transmitting device and a receiving device based onthe at least one parameter.

An apparatus comprises a switch to receive a data transmit signal and aprocessor to control the switch to communicate the data transmit signalaway from a power amplifier in a first state, and to communicate thedata transmit signal to the power amplifier in a second state. Theprocessor may be configured to activate and deactivate the poweramplifier. The processor may also be configured to determine a linkquality from a transmitting device to a receiving device and control theswitch based on the link quality. The link quality may be based on areceived signal strength indication and a packet error ratio.

A method comprises receiving a data transmit signal and communicatingthe data transmit signal away from a power amplifier if a link qualityis above a first threshold. The data transmit signal is communicated tothe power amplifier if the link quality is below a second threshold. Thepower amplifier is deactivated if the link quality is above the firstthreshold. The link quality may be based on a received signal strengthindication.

An apparatus comprises means for controlling a switch to communicate adata transmit signal away from a power amplifier in a first state, orcommunicate the data transmit signal to the power amplifier in a secondstate based on the link quality of a communication channel. Theapparatus may also comprise one or more of: means for deactivating oractivating the power amplifier; and means for determining a link qualityfrom a transmitting device to a receiving device.

A computer readable storage medium has processor executable instructionsto determine a link quality of a communication channel and communicate adata transmit signal away from a power amplifier if the link quality isabove a first threshold or communicate the data transmit signal to thepower amplifier if the link quality is below a second threshold. Theprocessor executable instructions may also deactivate the poweramplifier if the link quality is above the first threshold and/orcontrol a switch in communication with the power amplifier based on thelink quality.

A method comprises activating a power amplifier if a link quality of acommunication channel is below a first threshold and deactivating thepower amplifier if the link quality is above a second threshold. A linkquality of the communication channel may be determined based upon areceived signal strength indication, as an example. A target datatransfer rate is maintained while the power amplifier is deactivated.The distance between a transmitting device having the power amplifierand a receiving device may be determined based on the link quality.

An apparatus comprises a processor configured to activate a poweramplifier if a link quality of a communication channel is below a firstthreshold and deactivate the power amplifier if the link quality isabove a second threshold. The processor may determine the link qualitybased upon a received signal strength indication and/or determine adistance between a transmitting device and a receiving device based onthe link quality.

An apparatus comprises means for activating or deactivating a poweramplifier based on a link quality of a communication channel. The linkquality may be based upon a received signal strength indication. Theapparatus may also include means for determining a distance between atransmitting device and a receiving device.

A computer readable storage medium has processor executable instructionsto activate a power amplifier if a link quality of a communicationchannel is below a first threshold and deactivate the power amplifier ifthe link quality is above a second threshold. The processor executableinstructions may also determine a distance between a transmitting deviceand a receiving device based on the link quality.

Other systems, methods, and features of the invention will be, or willbecome, apparent to one with skill in the art upon examination of thefollowing figures and detailed description. It is intended that all suchadditional systems, methods, features and advantages be included withinthis description, be within the scope of the invention, and be protectedby the following claims.

The preferred embodiments will now be described with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is block diagram of an embodiment of a power amplificationcontrol circuit of the present invention;

FIG. 2 illustrates a first distance between a transmitter and a receiverthat requires power amplification of a transmit signal;

FIG. 3 illustrates a second distance between a transmitter and areceiver that does not require power amplification of a transmit signal;

FIG. 4 shows acts of an embodiment of the present invention forcontrolling the amount of current supplied to a power amplifier;

FIG. 5( a) is a functional block diagram of a hard disk drive;

FIG. 5( b) is a functional block diagram of a digital versatile disk(DVD);

FIG. 5( c) is a functional block diagram of a high definitiontelevision;

FIG. 5( d) is a functional block diagram of a vehicle control system;

FIG. 5( e) is a functional block diagram of a cellular phone;

FIG. 5( f) is a functional block diagram of a set top box;

FIG. 5( g) is a functional block diagram of a media player; and

FIG. 5( h) is a functional block diagram of a VoIP phone.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The disclosure can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention. Moreover, in the figures, likereferenced numerals designate corresponding parts or elements throughoutthe different views.

The embodiments below relate to a power amplification control circuitfor selectively activating and deactivating a power amplifier in awireless transmitting device such as a laptop computer, a desktopcomputer, a cell phone, a personal digital assistant, a wirelesskeyboard, monitor, mouse, or other device. The power amplificationcontrol circuit includes a transmit power control circuit that regularlydetermines the quality of the communication channel from the wirelesstransmitting device to a receiving device. The receiving device may beany of the devices mentioned above or other device that receives awireless signal.

Based on the quality of the communication channel, the transmit powercontrol circuit controls a switching device between a data transmittercircuit and the transmitter's antenna. In a first state, the switchingdevice connects the data transmitter circuit to a power amplifier toincrease the strength of the data signal communicated to the antenna. Ina second state, the switching device disconnects and bypasses the poweramplifier. The power amplifier is turned off or otherwise reduced to aninactive state when the switch is in the second state, therebydecreasing the power consumed by the transmitting device and extendingthe life of the transmitting device's battery.

FIG. 1 is block diagram showing an embodiment of a power amplificationcontrol circuit 100. The power amplification control circuit 100includes a data transmitter circuit 102, such as a radio frequency (RF)transceiver or other circuit, a switch 106, a transmit power controlcircuit 108, a power amplifier 110, and an antenna 112. Components ofthe power amplification control circuit 100 may be part of a WLANintegrated circuit (chip) or other integrated circuit in a wirelessdevice, as examples. For example, in an embodiment a WLAN chip includesthe transmitter circuit 102, the switch 106, and the transmit powercontrol circuit 108. In this embodiment, the power amplifier 110 and theantenna 112 are external to the WLAN chip. In another embodiment, thepower amplifier 110 is also part of the WLAN chip and may be referred toas an “internal power amplifier.” The WLAN chip may include one or moreof the following devices (not shown) in communication with one or moreof the components of the power amplification control circuit 100: abaseband processor (BBP), a media access control (MAC) device, aphysical-layer (PHY) device, interfaces, firmware, memory, processors,or any other system on chip (SOC) components. Other integration schemesfor the components of the power amplification control circuit 100 arecontemplated and within the scope of the invention.

The transmitter circuit 102 includes a pre-power amplifier signal driver104 that outputs a data transmit signal. The data transmit signal isreceived by the switch 106. The switch 106 is in communication with andcontrolled by a processor 116. The switch 106 may be any type of switch,such as a general purpose input/output (GPIO) controlled switch, as anexample. The processor 116 is configured to control the switch 106 basedon the quality (also referred to as strength) of the communicationchannel (also referred to as the RF channel) from the poweramplification control circuit 100 to a receiving device (not shown). Thequality of the communication channel may be determined by the processor116 based on data related to the power present in the data signalreceived by the receiving device, the number of data errors reported tothe transmitting device by the receiving device, and/or by some othermethod that determines the quality of a communication channel. Anexample of a communication channel quality measurement is a receivedsignal strength indication (RSSI). RSSI values are determined by thereceiving device and reported back to the transmitting device. Anexample of a measurement of data error indicative of the quality of acommunication channel is the packet error ratio (PER). The PER isdetermined by the receiving device and reported back to the transmittingdevice. The communication channel quality as indicated by RSSI or PERmay be expressed as a value having arbitrary units, such as LQ (linkquality). A rising LQ value may be indicative that the transmittingdevice and receiving device are moving closer together. Likewise, afalling LQ value may be indicative that the transmitting device andreceiving device are moving further apart. Regardless of whether thedevices are moving closer together or further apart, a changing LQ valueindicates that the quality of the communication channel is increasing ordecreasing.

The processor 116 may be a hardware, software, or firmware processorconfigured to control the switch 106 and the power amplifier 110 basedon the quality of the communication channel as indicated by an RSSI,PER, LQ, and/or other value. Hereinafter, for clarity of explanation thequality of the communication channel will be considered an LQ value,although additional or other values and/or parameters may be relied uponas an indication of the quality of the communication channel.

In an embodiment, if the processor 116 determines that the quality ofthe communication channel is above a first link quality (LQ₁) threshold,it communicates a control signal to the switch 106 to bypass the poweramplifier 110. The control signal may also be communicated to the poweramplifier 110 to turn it off. In another embodiment, the processor 116communicates a separate signal to the power amplifier 110 to turn itoff. If the processor 116 determines that the quality of thecommunication channel is below a second link quality (LQ₂) threshold, itcommunicates a control signal to the switch 106 to include the poweramplifier 110 in the signal path to the antenna 112. The control signalmay also be communicated to the power amplifier 110 to turn it on.Alternatively, the processor 116 may communicate a separate signal tothe power amplifier 110 to turn it on.

FIGS. 2 and 3 illustrate an example of controlling the on/off state ofthe power amplifier 110 as the distance between the receiving device 204and the transmitting device 202 changes, as indicated by a changing LQvalue. It is to be understood that any specific values discussed beloware provided for explanatory purposes only and are not to be interpretedas limiting the scope of the invention.

In FIG. 2, the distance from the transmitting device 202 to thereceiving device 204 is expressed as d₁. In FIG. 3, the distance fromthe transmitting device 202 to the receiving device 204 is expressed asd₂, where d₂<d₁. By way of example, the transmitting device 202 may be alaptop computer and the receiving device 204 may be a Wi-Fi accesspoint. The distance d₁ may be 3 meters (or more) and the distance d₂ maybe 1 meter (or less), as an example.

In FIG. 2, the power amplifier 110 is on. Because the power amplifier110 also affects the LQ value, at distance d₁ with the power amplifier110 on the LQ value is high enough to maintain a target data transferrate. For example, at a distance d₁=3 meters the power amplifier 110 mayoutput a 17 dBm (dBm₁) signal. If the LQ is strong at 17 dBm, thereceiving device 204 will receive data at the target data transfer rate.The target data transfer rate may be, for example, the maximum (i.e.,device rated) or near maximum transmit rate for the devices 202, 204. Atd₁ with the power amplifier 110 on, the total power (mA₁) consumed bythe power amplification control circuit 100 is equal to the sum of thepower consumed by the transmitter circuit 102 and the power consumed bythe power amplifier 110 for transmitting the data signal.

FIG. 3 illustrates that the receiving device 204 has moved closer to thetransmitting device 202. The processor 116 may detect this movement by arising LQ value. In response to the rising LQ value, the processor 116switches the power amplifier 110 off and controls the switch 116 so thatthe transmit signal bypasses the power amplifier 110. In this state andat this distance (d₂), the signal strength (dBm₂) is provided by onlythe transmitter circuit 102. With the power amplifier 110 off andbypassed, the processor 116 continues to monitor RSSI and PER data todetermine whether the quality of the communication channel is above LQ₁,and strong enough to maintain the target data transfer rate. Providedthe communication channel continues to support the target data transferrate, the processor 116 maintains the state of the switch 106 and poweris preserved by having the power amplifier 110 off. The processor 116continues to monitor the quality of the communication channel todetermine whether to turn the power amplifier 110 on or off and controlthe switch 106 accordingly.

The power amplification control circuit 100 may be implemented asdiscussed above where the power amplifier 110 is in one or two states:either off or on. In this version, the power amplifier 110 has only oneamplification level. Alternatively, the power amplification controlcircuit 100 may control the power amplifier 110 to be off or to transmitat one of two or more selectable transmit power levels. In thisembodiment, the power amplification control circuit 100, upon detectinga wireless link of insufficient quality, adjusts the power level and/ordata rate of the transmitted signal to obtain successful transmissions.The processor 116 may iteratively adjust the power level of thetransmitted signal, via the power amplifier 110, and determine the LQ toachieve the target data transfer rate at the lowest power amplifier 110power level (including switching off the power amplifier 110).

FIG. 4 shows Acts 300 of an embodiment of the present invention forcontrolling the amount of power supplied to a power amplifier. The Acts300 of FIG. 4 include acts for switching on and off the power amplifier,as discussed above with reference to FIGS. 1-3, and acts forincrementally increasing and/or decreasing the amount of power suppliedto the power amplifier to adjust the LQ.

The Acts 300 of FIG. 4 are initiated at Act 304 every time interval T(Act 302). Time interval T may be one or several milliseconds, or anyother time interval, either fixed or updateable. RSSI and PER data arereferenced to determine the strength of the communication channel, whichmay include determining an LQ value, from a transmitting device to areceiving device (Act 302). If it is determined that the communicationchannel is not strong enough to support the maximum (or target) transmitrate of the transmitting and receiving devices (Act 306), it isdetermined whether the power amplifier is on or off (Act 308). If it isdetermined that the power amplifier is off, then the power amplifier isswitched on (Act 310). If the power amplifier is on, then it isdetermined whether the power amplifier is operating at its maximum(“high threshold”) power (Act 312). If the power amplifier is notoperating at its maximum power, the power to the power amplifier isincreased (Act 314). If the power amplifier is operating at its maximumpower, then the transmit data rate is decreased (Act 316) to obtainsuccessful transmissions.

Returning to Act 306, if it is determined that the communication channelis strong enough to support the maximum (or target) transmit rate of thetransmitting and receiving devices, it is determined whether thetransmitting device is transmitting at the maximum transmit rate (Act318). If the transmitting device is not transmitting at the maximumtransmit rate, the transmit rate is increased (Act 320). If thetransmitting device is transmitting at the maximum transmit rate, it isdetermined whether the power amplifier output power is at its minimum(“low threshold”) output power (Act 322). If the power amplifier outputpower is not at its minimum output power, the power amplifier outputpower is decreased (Act 324). If the power amplifier output power is ata minimum output power, the power amplifier is switched off (Act 326).As stated above, the Acts 300 may be repeated every time interval T toobtain successful transmissions at the lowest power amplifier powerlevel.

Further acts for incrementally increasing and/or decreasing the outputpower of a power amplifier are disclosed in U.S. patent application Ser.No. 10/962,376, entitled “Self-Adaptive Transmit Power Control forWireless Network,” filed on Oct. 8, 2004, the contents of which areincorporated herein by reference.

Referring now to FIGS. 5( a) to 5(h), various exemplary implementationsof the present invention are shown. Referring to FIG. 5( a), the presentinvention may be embodied in a hard disk drive (HDD) 400. HDD 400 maycommunicate with a host device (not shown) such as a computer, mobilecomputing devices such as personal digital assistants, cellular phones,media or MP3 players and the like, and/or other devices via a wirelesscommunication link 408.

The present invention may be implemented with either or both signalprocessing and/or control circuits, which are generally identified inFIG. 5( a) at 402. In some implementations, the signal processing and/orcontrol circuit 402 and/or other circuits (not shown) in the HDD 400 mayprocess data, perform coding and/or encryption, perform calculations,and/or format data that is output to and/or received from a magneticstorage medium 406. HDD 400 may be connected to memory 409, such asrandom access memory (RAM), a low latency nonvolatile memory such asflash memory, read only memory (ROM) and/or other suitable electronicdata storage.

Referring now to FIG. 5( b), the present invention may be implemented ina digital versatile disc (DVD) drive 410. The present invention may beimplemented in either or both signal processing and/or control circuits,which are generally identified in FIG. 5( b) at 412, and/or mass datastorage 418 of DVD drive 410. Signal processing and/or control circuit412 and/or other circuits (not shown) in DVD drive 410 may process data,perform coding and/or encryption, perform calculations, and/or formatdata that is read from and/or data written to an optical storage medium416. In some implementations, signal processing and/or control circuit412 and/or other circuits (not shown) in DVD drive 410 can also performother functions such as encoding and/or decoding and/or any other signalprocessing functions associated with a DVD drive.

DVD drive 410 may communicate with a device (not shown) such as acomputer, television or other device via a wireless communication link417. DVD drive 410 may communicate with mass data storage 418 thatstores data in a nonvolatile manner. Mass data storage 418 may include aHDD such as that shown in FIG. 5( a). The HDD may be a mini HDD thatincludes one or more platters having a diameter that is smaller thanapproximately 1.8″. DVD drive 410 may be connected to memory 419, suchas RAM, ROM, low latency nonvolatile memory such as flash memory, and/orother suitable electronic data storage.

Referring now to FIG. 5( c) the present invention may be embodied in ahigh definition television (HDTV) 420. The present invention may beimplemented in either or both signal processing and/or control circuits,which are generally identified in FIG. 6( c) at 422, a WLAN interface429 and/or mass data storage 427 of the HDTV 420. HDTV 420 may receiveHDTV input signals in a wireless format via a wireless communicationlink 424 and generate HDTV output signals for a display 426. In someimplementations, signal processing circuit and/or control circuit 422and/or other circuits (not shown) of HDTV 420 may process data, performcoding and/or encryption, perform calculations, format data and/orperform any other type of HDTV processing that may be required.

HDTV 420 may communicate with mass data storage 427 that stores data ina nonvolatile manner such as optical and/or magnetic storage devices. Atleast one HDD may have the configuration shown in either FIG. 5( a)and/or at least one DVD may have the configuration shown in FIG. 5( b).The HDD may be a mini HDD that includes one or more platters having adiameter that is smaller than approximately 1.8″. HDTV 420 may beconnected to memory 428 such as RAM, ROM, low latency nonvolatile memorysuch as flash memory and/or other suitable electronic data storage. HDTV420 also may support connections with a WLAN via a WLAN networkinterface 429.

Referring now to FIG. 5( d), the present invention may be implemented ina control system of a vehicle 430, a WLAN interface 448 and/or mass datastorage 446 of the vehicle control system. In some implementations, thepresent invention is implemented in a power-train control system 432that receives inputs from one or more sensors 436 such as temperaturesensors, pressure sensors, rotational sensors, airflow sensors and/orany other suitable sensors and/or that generates one or more outputcontrol signals such as engine operating parameters, transmissionoperating parameters, and/or other control signals at one or moreoutput(s) 438.

The present invention may also be embodied in other control systems 440of vehicle 430. Control system 440 may likewise receive signals frominput sensors 442 and/or output control signals to one or more output(s)444. In some implementations, control system 440 may be part of ananti-lock braking system (ABS), a navigation system, a telematicssystem, a vehicle telematics system, a lane departure system, anadaptive cruise control system, a vehicle entertainment system such as astereo, DVD, compact disc and the like. Still other implementations arecontemplated.

Powertrain control system 432 may communicate with mass data storage 446that stores data in a nonvolatile manner. Mass data storage 446 mayinclude optical and/or magnetic storage devices, for example HDDs and/orDVDs. At least one HDD may have the configuration shown in FIG. 5( a)and/or at least one DVD may have the configuration shown in FIG. 5( b).The HDD may be a mini HDD that includes one or more platters having adiameter that is smaller than approximately 1.8″. Powertrain controlsystem 432 may be connected to memory 447 such as RAM, ROM, low latencynonvolatile memory such as flash memory and/or other suitable electronicdata storage. Powertrain control system 432 also may support connectionswith a WLAN via a WLAN network interface 448. The control system 440 mayalso include mass data storage, memory and/or a WLAN interface (all notshown).

Referring now to FIG. 5( e), the present invention may be embodied in acellular phone 450 that may include a cellular antenna 451. The presentinvention may be implemented in either or both signal processing and/orcontrol circuits, which are generally identified in FIG. 5( e) at 452, aWLAN interface and/or mass data storage of the cellular phone 450. Insome implementations, cellular phone 450 includes a microphone 456, anaudio output 458 such as a speaker and/or audio output jack, a display460 and/or an input device 462 such as a keypad, pointing device, voiceactuation and/or other input device. Signal processing and/or controlcircuits 452 and/or other circuits (not shown) in cellular phone 450 mayprocess data, perform coding and/or encryption, perform calculations,format data and/or perform other cellular phone functions.

Cellular phone 450 may communicate with mass data storage 464 thatstores data in a nonvolatile manner such as optical and/or magneticstorage devices, for example HDDs and/or DVDs. At least one HDD may havea configuration shown in FIG. 5( a) and/or at least one DVD may have theconfiguration shown in FIG. 5( b). The HDD may be a mini HDD thatincludes one or more platters having a diameter that is smaller thanapproximately 1.8″. Cellular phone 450 may be connected to memory 466such as RAM, ROM, low latency nonvolatile memory such as flash memoryand/or other suitable electronic data storage. Cellular phone 450 alsomay support-connections with a WLAN via a WLAN network interface 468.

Referring now to FIG. 5( f), the present invention may be embodied in aset top box 480. The present invention may be implemented in either orboth signal processing and/or control circuits, which are generallyidentified in FIG. 5( f) at 484, a WLAN interface 496 and/or mass datastorage of the set top box 480. Set top box 480 receives signals from asource such as a broadband source and outputs standard and/or highdefinition audio/video signals suitable for a display 488 such as atelevision and/or monitor and/or other video and/or audio outputdevices. Signal processing and/or control circuits 484 and/or othercircuits (not shown) of the set top box 480 may process data, performcoding and/or encryption, perform calculations, format data and/orperform any other set top box function.

Set top box 480 may communicate with mass data storage 490 that storesdata in a nonvolatile manner. Mass data storage 490 may include opticaland/or magnetic storage devices, for example HDDs and/or DVDs. At leastone HDD may have a configuration shown in FIG. 5( a) and/or at least oneDVD may have the configuration shown in FIG. 5( b). The HDD may be amini HDD that includes one or more platters having a diameter that issmaller than approximately 1.8″. Set top box 480 may be connected tomemory 494 such as RAM, ROM, low latency nonvolatile memory such asflash memory and/or other suitable electronic data storage. Set top box480 also may support connections with a WLAN via a WLAN networkinterface 496.

Referring now to FIG. 5( g), the present invention may be embodied in amedia player 500. The present invention may be implemented in either orboth signal processing and/or control circuits, which are generallyidentified in FIG. 5( g) at 504, a WLAN interface and/or mass datastorage of the media player 500. In some implementations, media player500 includes a display 507 and/or a user input 508 such as a keypad,touchpad and the like. In some implementations, media player 500 mayemploy a graphical user interface (GUI) that typically employs menus,drop down menus, icons and/or a point-and-click interface via display507 and/or user input 508. Media player 500 further includes an audiooutput 509 such as a speaker and/or audio output jack. Signal processingand/or control circuits 504 and/or other circuits (not shown) of mediaplayer 500 may process data, perform coding and/or encryption, performcalculations, format data and/or perform any other media playerfunction.

Media player 500 may communicate with mass data storage 510 that storesdata such as compressed audio and/or video content in a nonvolatilemanner. In some implementations, the compressed audio files includefiles that are compliant with MP3 format or other suitable compressedaudio and/or video formats. The mass data storage 510 may includeoptical and/or magnetic storage devices, for example HDDs and/or DVDs.At least one HDD may have a configuration shown in FIG. 5( a) and/or atleast one DVD may have the configuration shown in FIG. 5( b). The HDDmay be a mini HDD that includes one or more platters having a diameterthat is smaller than approximately 1.8″.

Media player 500 may be connected to memory 514 such as RAM, ROM, lowlatency nonvolatile memory such as flash memory and/or other suitableelectronic data storage. Media player 500 also may support connectionswith a WLAN via a WLAN network interface 516. Still otherimplementations in addition to those described above are contemplated.

Referring to FIG. 5( h), the present invention may be embodied in aVoice over Internet Protocol (VoIP) phone 550 that may include anantenna 518. The present invention may be implemented in either or bothsignal processing and/or control circuits, which are generallyidentified in FIG. 5( h) at 520, a wireless interface and/or mass datastorage of the VoIP phone 550. In some implementations, VoIP phone 550includes, in part, a microphone 524, an audio output 526 such as aspeaker and/or audio output jack, a display monitor 528, an input device530 such as a keypad, pointing device, voice actuation and/or otherinput devices, and a Wi-Fi communication module 532. Signal processingand/or control circuits 520 and/or other circuits (not shown) in VoIPphone 550 may process data, perform coding and/or encryption, performcalculations, format data and/or perform other VoIP phone functions.

VoIP phone 550 may communicate with mass data storage 522 that storesdata in a nonvolatile manner such as optical and/or magnetic storagedevices, for example HDDs and/or DVDs. At least one HDD may have aconfiguration shown in FIG. 5( a) and/or at least one DVD may have theconfiguration shown in FIG. 5( b). The HDD may be a mini HDD thatincludes one or more platters having a diameter that is smaller thanapproximately 1.8″. VoIP phone 550 may be connected to memory 534, whichmay be a RAM, ROM, low latency nonvolatile memory such as flash memoryand/or other suitable electronic data storage. VoIP phone 550 isconfigured to establish communications link with a VoIP network (notshown) via Wi-Fi communication module 532.

All of the discussion above, regardless of the particular implementationbeing described, is exemplary in nature, rather than limiting. Althoughspecific components of the power amplifier control circuit aredescribed, methods, systems, and articles of manufacture consistent withpower amplifier control circuit the may include additional or differentcomponents. For example, components of the power amplifier controlcircuit may be implemented by one or more of: control logic, hardware, amicroprocessor, microcontroller, application specific integrated circuit(ASIC), discrete logic, or a combination of circuits and/or logic.Further, although selected aspects, features, or components of theimplementations are depicted as hardware or software, all or part of thesystems and methods consistent with the power amplifier control circuitmay be stored on, distributed across, or read from machine-readablemedia, for example, secondary storage devices such as hard disks, floppydisks, and CD-ROMs; a signal received from a network; or other forms ofROM or RAM either currently known or later developed. Any act orcombination of acts may be stored as instructions in computer readablestorage medium. Memories may be DRAM, SRAM, Flash or any other type ofmemory. Programs may be parts of a single program, separate programs, ordistributed across several memories and processors.

The processing capability of the system may be distributed amongmultiple system components, such as among multiple processors andmemories, optionally including multiple distributed processing systems.Parameters, databases, and other data structures may be separatelystored and managed, may be incorporated into a single memory ordatabase, may be logically and physically organized in many differentways, and may implemented in many ways, including data structures suchas linked lists, hash tables, or implicit storage mechanisms. Programsand rule sets may be parts of a single program or rule set, separateprograms or rule sets, or distributed across several memories andprocessors.

It is intended that the foregoing detailed description be understood asan illustration of selected forms that the invention can take and not asa definition of the invention. It is only the following claims,including all equivalents, that are intended to define the scope of thisinvention.

What is claimed is:
 1. A processor for controlling transmission of adata signal over a channel, the processor configured to: determinewhether the channel supports transmission of the data signal at atransmit rate; control a transmitter to adjust the transmit rate towarda predetermined transmit rate; and control a power amplifier to adjustan output power level of the power amplifier toward a predeterminedoutput power level that supports communication of the data signal overthe channel at the transmit rate, wherein if the transmit rate equalsthe predetermined transmit rate and the output power level is at leastat the predetermined output power level, the processor controls a switchto bypass the power amplifier.
 2. The processor of claim 1, whereinwhile the processor adjusts the output power level toward thepredetermined output power level, the processor is configured toiteratively: control the power amplifier to decrease the output powerlevel downward toward the predetermined output power level by an amount;and determine whether the channel supports transmission of the datasignal at the output power level.
 3. The processor of claim 1, whereinwhile the processor adjusts the transmit rate toward the predeterminedtransmit rate, the processor is configured to iteratively: control thetransmitter to increase the transmit rate upward toward thepredetermined transmit rate by an amount; and determine whether thechannel supports transmission of the data signal at the transmit rate.4. The processor of claim 1, wherein the predetermined output powerlevel is a first predetermined output power level, and if the channeldoes not support transmission of the data signal at the predeterminedtransmit rate, the processor is further configured to iteratively:control the power amplifier to increase the output power level upwardtoward a second predetermined output power level by an amount, whereinthe second predetermined output power level is greater than the firstpredetermined output power level; and determine whether the channelsupports transmission of the data signal at the output power level. 5.The processor of claim 4, wherein the predetermined transmit rate is afirst predetermined transmit rate, and if the output power level is atthe second predetermined output power level and the channel does notsupport transmission of the data signal, the processor is furtherconfigured to iteratively: control the transmitter to decrease the datasignal transmit rate downward toward a second predetermined transmitrate by an amount, wherein the second predetermined transmit rate islower than the first predetermined transmit rate; and determine whetherthe channel supports transmission of the data signal at the transmitrate.
 6. The processor of claim 1 wherein the processor determineswhether the channel supports transmission of the data signal based on atleast one of: a successful data transfer from the transmitter to areceiving device, a received signal strength indication, and a packeterror ratio.
 7. The processor of claim 1 wherein the processor controlsthe switch to maintain a target data transfer rate.
 8. A wireless localarea network chip including the processor of claim
 1. 9. An apparatusfor transmitting a data signal over a channel, the apparatus comprising:a transmitter configured to transmit the data signal at a transmit rate;a power amplifier configured to amplify the data signal to an outputpower level and to communicate the data signal to an output of theapparatus; a switch configured to selectively route the data signal fromthe transmitter to the output of the apparatus to thereby selectivelybypass the power amplifier; a processor configured to determine whetherthe channel supports transmission of the data signal at the transmitrate, wherein the processor is further configured to: control thetransmitter to adjust the transmit rate to a predetermined transmit rateand control the power amplifier to adjust the output power level to apredetermined output power level that supports communication of the datasignal over the channel at the transmit rate, wherein if the transmitrate equals the predetermined transmit rate and the output power levelis at least at the predetermined power output level, the processorcontrols the switch to bypass the power amplifier.
 10. The apparatus ofclaim 9, wherein while the processor adjusts the output power leveltoward the predetermined output power level, the processor is configuredto iteratively: control the power amplifier to decrease the output powerlevel downward toward the predetermined output power level by an amount;and determine whether the channel supports transmission of the datasignal at the output power level.
 11. The apparatus of claim 9, whereinwhile the processor adjusts the transmit rate toward the predeterminedtransmit rate, the processor is configured to iteratively: control thetransmitter to increase the transmit rate upward toward thepredetermined transmit rate by an amount; and determine whether thechannel supports transmission of the data signal at the transmit rate.12. The apparatus of claim 9, wherein the predetermined output powerlevel is a first predetermined output power level, and if the channeldoes not support transmission of the data signal at the predeterminedtransmit rate, the processor is further configured to iteratively:control the power amplifier to increase the output power level upwardtoward a second predetermined output power level by an amount, whereinthe second predetermined output power level is greater than the firstpredetermined output power level; and determine whether the channelsupports transmission of the data signal at the output power level. 13.The apparatus of claim 12, wherein the predetermined transmit rate is afirst predetermined transmit rate, and if the output power level is atthe second predetermined output power level and the channel does notsupport transmission of the data signal, the processor is furtherconfigured to iteratively: control the transmitter to decrease the datasignal transmit rate downward toward a second predetermined transmitrate by an amount, wherein the second predetermined transmit rate islower than the first predetermined transmit rate; and determine whetherthe channel supports transmission of the data signal at the transmitrate.
 14. The apparatus of claim 9 wherein the processor determineswhether the channel supports transmission of the data signal based on atlease one of: a successful data transfer from the transmitter to areceiving device, a received signal strength indication, a packet errorratio.
 15. The apparatus of claim 9 wherein the processor controls theswitch to maintain a target data transfer rate.
 16. A wireless localarea network chip including the apparatus of claim
 9. 17. A method fortransmitting a data signal over a channel, the method comprising:determining, by a processor, whether the channel supports transmissionof the data signal at a transmit rate; controlling a transmitter toadjust the transmit rate toward a predetermined transmit rate; andcontrolling a power amplifier to adjust an output power level to apredetermined output power level that supports communication of the datasignal over the channel at the transmit rate; and if the transmit rateequals the predetermined transmit rate and the output power level is atleast at the predetermined power output level, controlling a switch tobypass the power amplifier.
 18. The method of claim 17, furthercomprising iteratively: controlling the power amplifier to decrease theoutput power level downward toward the predetermined output power levelby an amount; and determining whether the channel supports transmissionof the data signal at the output power level.
 19. The method of claim17, further comprising iteratively: controlling the transmitter toincrease the transmit rate upward toward the predetermined transmit rateby an amount; and determining whether the channel supports transmissionof the data signal at the transmit rate.
 20. The method of claim 17,wherein the predetermined output power level is a first predeterminedoutput power level, and if the channel does not support transmission ofthe data signal at the predetermined transmit rate, the method furthercomprises iteratively: controlling the power amplifier to increase theoutput power level upward toward a second predetermined output powerlevel by an amount, wherein the second predetermined output power levelis greater than the first predetermined output power level; anddetermining whether the channel supports transmission of the data signalat the output power level.
 21. The method of claim 20, wherein thepredetermined transmit rate is a first predetermined transmit rate, andif the output power level is at the second predetermined output powerlevel and the channel does not support transmission of the data signal,the method further comprises iteratively: controlling the transmitter todecrease the data signal transmit rate downward toward a secondpredetermined transmit rate by an amount, wherein the secondpredetermined transmit rate is lower than the first predeterminedtransmit rate; and determining whether the channel supports transmissionof the data signal at the transmit rate.